1. Field of the Invention
The present invention relates to a semiconductor device. More particularly, the present invention relates to a metal oxide semiconductor (MOS) device.
2. Description of the Related Art
Liquid crystal display (LCD) has become the main stream of the display apparatuses. Due to its advantages of light-weight, compact, applicable in various sizes and low radiation, the LCD is suitably used as the display screen for portable electronic apparatuses such as the notebooks, the mobile phones and global positioning systems (GPS) etc.
Owing to the limited power capacity of the battery, it is desirable for the LCDs used in the portable electronic apparatuses to offer lower electricity consumption. However, as the size of the LCD panels keeps increasing, the electricity consumption is inevitably increased.
In general, high voltage devices are widely used in the driver integrated circuits (ICs) of the LCD panels and the high voltage devices are fabricated using the complementary metal oxide semiconductor (CMOS) manufacturing processes. For the high voltage devices, the junction breakdown voltage of the source/drain region is raised by either forming the isolation layer to enlarge the distance between the source/drain region and the gate to lower the transversal electric field in the channel, or by performing lightly doping to the drift region under the isolation layer and the grade region under the source/drain region for relieving the hot electron effects.
For future advanced applications, it is acutely desirable to lower the power consumption of the driver ICs in the LCD panels.